Thymosin α 1 activates murine DCs on exposure to A fumigatus Murine lung CD11c⁺ DCs were pretreated with thymosin α 1 or the scrambled peptide (sThymosin α1) before the exposure to conidia or hyphae for the assessment of (A) phagocytosis, (B) costimulatory molecule expression, and (C) frequency of IL-12 p70-producing cells. (A) Assessment of phagocytosis (the data are the means ± SEs of 3 independent experiments and expressed as the percentage of internalization [numbers within figures]; ^*P < .05, thymosin-exposed versus unexposed cells). Cells were stained with Diff-Quik stain (Carlo Erba Reagents, Milan, Italy). Original magnification, ×100. (B) Costimulatory molecule expression by FACS analysis (data from one representative experiment of 3). Black histograms represent cells stained with an irrelevant antibody. The numbers refer to the median fluorescence intensity. (C) Frequency of IL-12 p70-producing cells (the values are the mean ± SE per 10⁵ cells of samples from 3-5 experiments, calculated by ELISPOT assay). ^*P < .05, exposed versus unexposed (None) or conidia-exposed cells.